0 votes 0 votes Can anyone explain how S2 is false,I did not understand their logic. Theory of Computation regular-expression theory-of-computation finite-automata regular-language expression made-easy-test-series + – sripo asked Jan 1, 2019 • edited Mar 4, 2019 by Rishi yadav sripo 665 views answer comment Share Follow See all 5 Comments See all 5 5 Comments reply Show 2 previous comments Manjyot Singh Nanra commented Jan 1, 2019 reply Follow Share Hey suppose Σ = {a,b} then we know Σ* = { epsilon , a, b, aa , ab, ba ,bb ,........} Here's definition of Language : A language is a set of string all of which are chosen from some ∑*, where ∑ is a particular alphabet. So a Language can be anything as well as : L = { epsilon } is also a valid language.( A language that excepts empty Now L* will obviously be L* = {epsilon} so , L* - {epsilon} = empty set. So second statement will not be always true. I have no formal answer but I hope this counter example I provided helps 2 votes 2 votes Magma commented Jan 1, 2019 reply Follow Share Nice Thanks :) 0 votes 0 votes sripo commented Jan 1, 2019 reply Follow Share This example helped thanks a lot :p 0 votes 0 votes Please log in or register to add a comment.
2 votes 2 votes Because L* will definitely contain Epsilon in it. Suppose L = {a,b}, then L* = { epsilon , a , b ,aa, ab, ba, bb, ........} Therefore L* - {epsilon} = {a, b, aa, ab, ba, bb, ..........} Thus L* - {epsilon} is not equal to L* Manjyot Singh Nanra answered Jan 1, 2019 Manjyot Singh Nanra comment Share Follow See all 2 Comments See all 2 2 Comments reply sripo commented Jan 1, 2019 reply Follow Share It's L+ not L* 0 votes 0 votes Manjyot Singh Nanra commented Jan 1, 2019 reply Follow Share sorry, the image was not clear. anyway this was my first answer and I don't know if we can delete our answers. Can we delete our answers? 0 votes 0 votes Please log in or register to add a comment.